基于因子分析的南湾水库水源地浮游植物生物完整性评价

Phytoplankton index of biotic integrity based on factor analysis for water source assessment

于2016年在淮河流域饮用水源地水库-南湾水库,开展了3次浮游植物调查,在分析南湾水库浮游植物群落结构的基础上,依据生物完整性理论,采用因子分析方法对南湾水库开展了生态完整性评价。研究结果显示:3次调查中浮游植物种类数变化较小,但所属种类存在明显的季节差异;浮游植物密度9月份最高,3月密度最低,而生物量则正好相反,3月最高而9月最低。进一步采用因子分析对群落数据进行分析,筛选确定了4个公因子。其中,因子1反映了群落的耐污特征与能力;因子2表征了群落的多样性特征;因子3表征了群落丰富度状况;因子4表征了水体富营养状况。因子分析得分表明:从时间上来看,南湾水库9月水生态状况最差,从空间上看,则人口密度大的库湾区域水生态状况较差。因子得分较好地反映了水库不同时间与地点水生态状况的相对大小,表明基于因子分析生物完整性评价能够较地应用于南湾水库,也适合推广应用于其他水体的生态评价工作中。

Currently, studies on the assessment of ecological integrity mainly focus on the development of the fish or benthic index of biotic integrity for rivers and lakes, and there are few studies on phytoplankton in reservoirs. Therefore, the phytoplankton communities were investigated three times in the Nanwan Reservoir, a water supply reservoir in the Huaihe River Basin in 2016. An ecological integrity assessment was conducted based on the phytoplankton biological integrity using factor analysis. The results showed that the number of phytoplankton species in the three investigations changed marginally, but there was a clear seasonal difference among the species. The density of phytoplankton was the highest in September and the lowest in March, but the biomass was the highest in March and the lowest in September. The factor analysis was used to further analyze and assess the ecological status. Four common factors were identified in the factor analysis. Among them, factor 1 characterizes the characteristics and ability of the community to resist pollution, factor 2 characterizes the diversity of the community, factor 3 characterizes the richness of the community, and factor 4 characterizes the eutrophication of the water body. The factor scores showed obvious difference in different months. The ecological condition in March was the best. Further, from the spatial point of view, the water ecological condition of the area with high population density was very poor.The factor score better reflects the relative size of the water ecological status of the reservoir at different times and locations. This indicates that the assessment of biological integrity based on factor analysis is suitable for the Nanwan Reservoir and can be applied to the ecological assessment of other water bodies.